In an effort to push more people to enroll in its yearly $99 Amazon Prime program, Amazon is now limiting the amount of users that can share the benefits of using Prime.

With an estimated 40 million Prime subscribers in the United States alone, Amazon Prime has certainly transformed from being a loss leader a decade ago to one of Amazon's lucrative revenue generators, as Prime members are known to buy more with their two-day free-shipping benefit.

However, now that many users have had a taste of how Prime works, Amazon is now cutting back the sharing benefits to just two persons and four children in one household. Previously, Prime members can share their benefits to four other people. With the new terms quietly rolled out by Amazon, the sharing benefits are absorbed into Amazon Household.

Beginning Aug. 1, any two people sharing their Prime benefits will be able to access each other's credit and debit cards, which is not much of a problem for spouses sharing the same financial obligations. However, there are couples who prefer to manage their finances separately and will also definitely discourage anybody from sharing their account with friends and coworkers.

"In order to share content, Prime benefits and Amazon Mom benefits, both adult account holders need to authorize each other to use credit and debit cards associated with their Amazon accounts for purchases on Amazon," the new terms say. "This will not affect either of their current payment settings, but each adult will be able to copy the credit and debit cards of the other account to his or her Amazon account and use them for purchases on Amazon."

Under the new terms, users sharing Prime benefits will be able to share more. In the past, only the free shipping option could be shared with others. However, Amazon Household will let two users take advantage of free shipping as well as Amazon Instant Video, Kindle Owners' Lending Library, Prime Early Access and deals from Prime Exclusive.

Currently, Prime members who have four other people enrolled into their accounts can still share their free shipping benefits with them. However, once a member is removed, they can no longer receive the benefits and will have to enroll their own Prime account. Also, when Prime members renew their yearly subscriptions, they will be limited to sharing their benefits with just one adult and four children under Amazon Household.

Photo: Mike Seyfang | Flickr